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Biorational Disease Control

Biorational disease control products (fungicides, bactericides, and nematicides) fall into the same classes as the insecticides, botanicals, minerals, and synthetics. Sulfur, potassium bicarbonate, phosphites and copper compounds are examples of minerals or synthetics that can control fungal and bacterial diseases. Organic growers should be sure to check with their certifying authority for more information on these materials. Botanicals such as rosemary oil, soybean oil, or garlic extracts appear in this table and are generally approved for use in organic production. These products require thorough coverage, application at the first signs of disease, and frequent repeated dosages to be effective.

Microbial products are all living organisms that require specialized storage and application procedures. These include beneficial fungi and bacteria (Streptomyces, Gliocladium, Trichoderma harizanum) that compete with plant pathogenic fungi, produce toxic metabolites, or actively parasitize pathogens. Their effectiveness in University research trials has been inconsistent because of variations in environmental conditions and disease pressure. Microbial fungicides perform best in a greenhouse environment where they can establish and flourish. Control of plant pathogenic organisms on the phylloplane (leaf surface) is especially problematic, as the competing organisms must establish themselves and can fail due to dessication and exposure to sunlight. These materials have a limited shelf life, must be protected from temperature extremes, and correctly applied (plenty of water and under the correct environmental conditions) to be effective.

Table 10. Biorational Insect and Mite Control Materials.
Active Ingredient Trade Name(s) Target Pests Comments
azadiractin Aza-Direct, Azatin XL,
Aphids, leafminers, thrips, whitefly, leafhopper, flies, true bugs, some beetles and caterpillars Insect growth regulator, repellent, antifeedant. Disrupts growth of immature stages. Use preventatively before outbreaks. Repeat applications may be needed. Efficacy varies.
Beauvaria bassiana
strain GHA
Mycotrol O,
BotaniGard 22WP
Aphids, whiteflies, thrips This fungus penetrates the insect cuticle, proliferates and eventually releases new spores. Best applied in evening. Use preventatively based on monitoring before pest populations are high.
Bacillus thuringiensis
subsp. kurstaki

Caterpillars, including cranberry/cherry fruitworm, blueberry sawfly, winter moth, grape berry moth, leafrollers, etc. Acts as stomach poison, must be ingested to be effective. Not all products are OMRI listed; check the label.
Bacillus thuringiensis
subsp. aizawai
Agree WG Caterpillars, including armyworms, grapeleaf skeletonizer Acts as stomach poison, must be ingested to be effective. OMRI listed.
bifenzate Acramite 50WS,
Floramite SC
Mites A long residual selective nerve poison for mite control.

Burkholderia spp.
strain A396
Venerate Caterpillars, scale insects Highly active against grape berry moth.  Make two applications 7-days apart for each generation when needed.
Grandevo and Venerate can be rotated but do not tank-mix the two products together.

Chromobacterium subtsugae
strain PRAA4-1
Grandevo Grape berry moth, mites, spotted wing drosophila suppression Early application is important for Grandevo against any of the sucking pests as the primary MOA is reduction in reproduction and typically a 7-day application interval or shorter is needed. 
Highly active against grape berry moth.  Make 2 applications 7 days apart for each generation when needed.
Grandevo WDG at 3 lb/acre + adjuvant for spotted wing drosophila.
extract of neem oil Trilogy Primarily labeled for (but not limited to) mite control Can be used to control mites. For best results use when population levels are low to prevent build-up. Repeat applications are needed. Do use on table grapes after bloom or on wine grapes after bunch closure.
potassium salts of fatty acids (insecticidal soaps) M-Pede, Des-X Aphids, leafminers, mites, thrips, whiteflies Works on contact. Can be phytotoxic to some crops, test on small plot first. Avoid treatment when plants are stressed or air temperatures are above 85˚F. May also harm some beneficials. Also active against powdery mildew. Do not use on table grapes onces they become 6-7 mm or use at lowest recommended rate (75 gal/A)
iron phosphate Sluggo Snails, slugs Bait which causes feeding to cease. Death occurs over 3-5 days. Exempt from tolerance and has a zero hour reentry interval due to low mamalian toxicity.
methoxyfenozide Intrepid Many species of caterpillar Insect Growth Regulator. Mimics molting hormone; causes premature molt and death. Labeled for Grape Berry Moth.
pyrethrin Pyganic EC,
Pyrenone Crop Spray
Many pests of fruit crops; see label. Botanical insecticide with broad-spectrum activity. Contact toxin with rapid knockdown bur short residual. Highly toxic to fish. Derived from chrysanthemum. Some formulations OMRI listed.
spinosad Entrust 2SC Caterpillars, leafminers, thrips Acts both as a contact and stomach poison. Somewhat toxic to some beneficials. Rotate with other selective biorationals to prevent the development of resistance.
spiromesifen Oberon Whiteflies and some mites Contact insecticide and miticide.
Steinernema and Heterohabditis
parasitic nematode species
Beneficial Nematodes White grubs, weevil larvae, wireworms Predatory nematodes seek out and penetrate host insects, multiply within the host and kill it. They are most likely to be effective against soil-dwelling immature stages of susceptible host insects. They require moist soil conditions to survive.
Table 11. Biorational Disease Control Materials
Active Ingredient Trade Name(s) Target Pests Comments
Acibenzolar-S-methyl Actigard 50 WG Downy mildew, Xanthomonas Plant defense activator.
Bacillus amyloliquefaciens Triathlon, Double Nickel Botrytis, Alternaria, fungal leaf spots and blights, Powdery mildew Most recommendations are to mix Double Nickel with Cueva.
Bacillus pumilus strain QST 2808 Sonata Powdery mildew, rust, leaf spots  
Bacillus subtilis QST Serenade Max Botrytis, leaf spot, Anthracnose, Powdery mildew  
Calcium polysulfide Lime-Sulfur (various manufacturers) Cane and spur blights, Phomopsis, Fusicocum, overwintering inoculum of Monolinia This is a caustic compound that must be thoroughly cleaned from spray equipment to avoid damage. Some formulations are OMRI listed.
Copper hydroxide Champion WP, Champ, Nu-Cop, Kocide Botrytis, Downy mildew, Powdery mildew, Anthracnose, Phomopsis Be careful of potential phytotoxicity in some crops or cultivars; do not apply in close succession with Captan; read label carefully for cautions and restrictions.
Copper octanoate Cueva Powdery mildew, leaf spots, Anthracnose, Botrytis
Copper sulfate Cuprofix-Ultra 40 Disperss Powdery mildew, leaf spots, Anthracnose  
Harpin protein Messenger Bacterial diseases, adverse environmental conditions Plant defense activator; variable efficacy
Hydrogen dioxide Oxidate Alternaria, Phytophthora, Pythium, Rhizoctonia, Anthracnose, Botrytis, Powdery mildew Kills on contact by oxidation. Will also kill beneficial organisms. Requires repeated applications.
Kaolin clay Surround WP Powdery mildew, heat stress, sunscald Creates a thin film of clay particles on the surface of treated plants. Must be rinsed off of harvested fruit if residue persists.
 Laminaria digitata plant extract Vacciplant Botrytis, Anthracnose, mummyberry Plant defense activator. Start applications preventatively or when conditions for disease development become favorable. Reapply every 7 – 14 days. Under moderate to heavy disease pressure, tank mix this product with another registered fungicide.
Neem oil Trilogy
Anthracnose, Botrytis, Downy and Powdery mildew Also effective for insect and mite control. Repeat applications needed for good control.
Potassium bicarbonate Kaligreen
Alternaria, Botrytis, Downy and Powdery mildew  
Potassium phosphite ProPhyt, Phostrol Downy mildew, Phytophthora Systemic material
Mono- and dibasic sodium, potassium, and ammonium phosphites Phostrol Downy mildew, Pythium, Phytophthora Systemic material, see label for tank mix cautions
Pseudomonas fluorescens BlightBan A506 Strawberry frost protection and grape bunch rot protection
For strawberry frost protection, start application when first bloom initials emerging from crown. Repeat treatments as necessary, with a total of 2-3 applications.
As an aid to control bunch rot caused by species of Acetobacter bacteria (sour rot) in combination with Aspergillus niger and Botrytis cinerea. Apply at bloom and again prior to bunch closure.
Reynoutria sachaliensis (giant knotweed) Extract Regalia Botrytis, Anthracnose, mummyberry Plant extract to boost plants’ defense mechanisms to protect against certain fungal and bacterial diseases, and to improve plant health.
Applications need to start early.
Regalia + NuFilm P for control of mummyberry and anthracnose fruit rot.
Streptomyces lydicus Actinovate AG Powdery mildew, Botrytis  



Powdery mildew Be careful of potential phytotoxicity in some crops or cultivars; do not apply in close succession with Captan; read label carefully for cautions and restrictions.